International Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 5. Hakodate 1998 
Method of sequential image analysis 
with telescopic pole for traffic flow measurement 
Hiroshi TAKEDA, Masahiro SETOJIMA, Naruo MUSHIAKE 
Image Analysis Section Engineer, Department of Emviroment 
KOKUSAI KOGYO Co., LTD 
Yoshiaki YOSHINO, Jinkei TAMADA 
Ministry of Construction 
5 Sanban-cho, Chiyoda-ku, Tokyo, 102-0075 
JAPAN 
Commission V, Working Group IC V/III 
1. Introduction 
An increasing number of traffic flow 
measurement systems equipped with video 
cameras are being used.” ? These measurement 
systems are used to determine the number of 
vehicles, vehicle velocity, and vehicle type. Most 
of these traffic flow measurement cameras are 
stationary, installed along expressways and 
major highways.” Because of economical and 
locational conditions, installation of stationary 
cameras along general roads is difficult in many 
cases. 
In this study, portable telescopic poles were 
used for observation and measurement of traffic 
flow on general roads. Cameras mounted on 
telescopic poles used in the study could be 
extended up to 20m for observation. This 
permitted observation measurements to be taken 
from viewpoints higher than ordinary stationary 
cameras. In addition, the use of telescopic pole 
cameras offered high-precision measurement by 
allowing points directly under the camera to be 
recorded. 
In the study, the speed, length and number of 
test vehicles passing through a linear section of 
a general highway were measured by spatio- 
temporal image analysis. The study was 
conducted in order to examine the possibility of 
determining vehicle type on the basis of the 
measured vehicle length. Loci of traveling 
vehicles were also measured in a test road 
section modeled after an intersection. 
2. Equipment 
Observation of general roads other than 
expressways and major highways may need 
multiple observation points, so installation of 
stationary cameras will be difficult. The 
installation height of ordinary stationary cameras 
is low. As a result, the observation angle with 
respect to the ground is less, reducing the 
measurement accuracy of spatial depth, when it 
is intended to ensure a wide observation area. 
In this study, telescopic poles (Fig.1) were used 
as observation platforms. The main focuses of 
the observation were to stress the importance of 
the mobility of these poles and the stability of the 
video cameras, when taking measurements from 
an elevated position during the observations. 
These motor-driven telescopic poles can extend 
from 3 m to 15 m above ground. The telescopic 
pole is mounted on a caterpillar, which permits 
the telescopic pole to be moved over short 
distances. In addition, because the telescopic 
poles may be loaded onto trucks, they can be 
transported over long distances. 
Use of telescopic poles ensures stable images 
observed from a high view point and may even 
be used on general roads in areas where there 
are no high-rise buildings on which to mount 
cameras. Table 1 shows specifications for 
equipment of telescopic poles. 
Table 1 Specifications for equipment 
  
  
  
  
  
  
  
  
item spec 
(1) body 
max. length 19.84m 
min. length 2.95m 
pole diameter 280mm 
motor box size 410x563mm 
weight 185kg 
material Carbon FRP 
  
permitted weight |10kg 
  
expansion speed |1.7m/min. 
  
(2) video camera 
  
  
  
  
body size 70x72x124mm 
weight 0.67kg 
focus of lens 7.5-90mm 
iris F1.4-F16 
  
  
  
  
CCD type interlace 1/2inch 
  
  
    
   
   
   
  
  
  
   
   
   
   
   
    
    
   
   
     
   
     
     
   
   
   
   
     
   
   
    
     
   
   
     
    
     
   
    
    
   
     
  
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